From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2D1C6302767; Wed, 20 May 2026 02:41:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779244866; cv=none; b=nqcY9IfnpVngLIDH6QbTwzPM1UxdSaainoQZSRyaAg7+f6Eda+UPMvrFeaxfNXdvUDbAbttNRYXlAGz4sUmJ33pDgk3OQO1HGy3KwnPmsOaDW3UiEyid1huHazfpJLUYHp8ttmjgsjUuwBwf3YfkW+qw3w4zS7Mg4mjSE05SY/M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779244866; c=relaxed/simple; bh=6ua6dP85AQ4nt7D+K3js7WWrh6A4zjLkDywplN3PGKA=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=btH/SkfwOfwHM4HlUXfkCEti8LtfV4qh6Gn0Hz7BmdtHBX71FieXZuwBI9UBX2dUwuSjXprLqg5rnBJ14rRxUogpixAstW/PippKev5Qksa4zE/gmDJguuwf29+VW1BTQ4g8sZu2y8ppwlfyB0RVNU4KRCc/tdUB+pfPyfomiM8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hyFsjlax; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="hyFsjlax" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B49AC1F000E9; Wed, 20 May 2026 02:41:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779244864; bh=zjuBdR5RduBCHJPTdjqDQAN29h+i6CofW+fqVD6Ur5U=; h=From:To:Cc:Subject:Date; b=hyFsjlax2RJH1df6Mi4nleaWvlH0R0J/97bhiUi68OnAqzPicf2kUR0UIiWBcIRps v5O3xHzahZi+RBMbY7ivw9zyvd/jaSwoFGuqJR6QMUZQXDxIYU+FIoczMIWSX4VAgv JWJLHKc+B8mKRuyeIuWeQcFULjfGGbr2+lqEDZxC89OF33np29E//fR4WLNtw4MJLq jh9pRX+eNNDdIsvsSc0d+toQrYAjUC9nGm4+tNoC5MmRUt6jrgNN73BVfYsSQAaOTJ orslEbZpsQz2PBWhuAzO7m1WJ5Bj+9p6opDi4uce718OXCdixAGvproETgOP2XQuij It6qtDibWf1cg== From: KP Singh To: bpf@vger.kernel.org, linux-security-module@vger.kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, Xianrui Dong , KP Singh Subject: [PATCH v2] bpf: reject NULL data/sig in bpf_verify_pkcs7_signature Date: Wed, 20 May 2026 04:40:59 +0200 Message-ID: <20260520024059.313468-1-kpsingh@kernel.org> X-Mailer: git-send-email 2.53.0 Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit __bpf_dynptr_data() can return NULL (FILE dynptrs, any non-contiguous backing). bpf_verify_pkcs7_signature() forwards the pointer to verify_pkcs7_signature() unchecked, causing a NULL deref in asn1_ber_decoder() reachable from a sleepable BPF LSM at lsm.s/bpf. NULL-check both pointers and reject with -EINVAL. Mirrors the guards already in kernel/bpf/crypto.c. Fixes: 865b0566d8f1 ("bpf: Add bpf_verify_pkcs7_signature() kfunc") Reported-by: Xianrui Dong Signed-off-by: KP Singh --- kernel/bpf/helpers.c | 5 +++++ tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c | 2 +- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 2bb60200c266..b5314c9fed3c 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -4241,8 +4241,13 @@ __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_p, data_len = __bpf_dynptr_size(data_ptr); data = __bpf_dynptr_data(data_ptr, data_len); + if (!data) + return -EINVAL; + sig_len = __bpf_dynptr_size(sig_ptr); sig = __bpf_dynptr_data(sig_ptr, sig_len); + if (!sig) + return -EINVAL; return verify_pkcs7_signature(data, data_len, sig, sig_len, trusted_keyring->key, diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c b/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c index 8cd298b78e44..04aaf4c9cf5e 100644 --- a/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c +++ b/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c @@ -14,7 +14,7 @@ static struct { const char *prog_name; int expected_runtime_err; } kfunc_dynptr_tests[] = { - {"dynptr_data_null", -EBADMSG}, + {"dynptr_data_null", -EINVAL}, }; static bool kfunc_not_supported; -- 2.53.0